Apparatus for producing staple fibers



Feb. 18, 1941. w. P. THOMPSON APPARATUS FOR PRODUCING STAPLE FIBERS Fild June 6, 1940 2 Sheets-Sheet 1 INVENTOR YBY ATTORNEY Feb. 18, 1941 w THQMPSQN 2,232,496 7 APPARATUS FOR PRODUCING STAPLE FIBERS Filed June 6, 1940 v2 Sheets-Sheet 2 MZ/amPmsionJZamasoh INVENTOR ATTORNEY Patented Feb. 18, 1941 PATENT OFFICE 2,232,496 APPARATUS. FOR PRODUCING STAPLE FIBERS Y Willard Preston Thompsomwaynesboro, Va., as-

- signor to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware Application June 6, 1940, Serial No. 339,065

'7 Claims.

This invention relates to a device for maintaining uniform the length of staple cut from continuous filaments. More particularly, it relates to a device for collecting and removing unusually long fibers during the cutting of staple from a rope or bundle of continuous filaments.

In the production of staple by cutting continuous filaments of rayonor the like to a' desired length, it is important that in any given production the length of the staple be substantially constant. Excessively long lengths of fibers, for instance,fibers which are 2', 3 or more times the length of the staple fibers being cut cannot be tolerated.

l Excessively long lengths of fibers may occur in the cut staple when it is produced by the cutting apparatus described in U. S. Patent No. 1,723,998 or by the use of similar apparatus in which the filament bundle is advanced, and held taut during the cutting operation, by means of centrifugal force. In staple cutting apparatus of this type the rope of continuous filaments, in passing through the feeding conduit to the cutting knife, sometimes momentarily piles up'and when suddenly released, a rope'of cut filaments several times the length desired may be produced; In

some cases these lengths may be as much as 30 or more inches. Also, if the operator permits the ends of the ropes to run past the feed. rolls, the

30 length extending from the bite of the feed roll to the discharge end of the tube through which the rope passes may be discharged into the bin along with the other cut staple. Depending upon the specific design of the cutter, this end length may also be 20, 30 or'more inches in length.

Again, the cutter may out only a part of the filaments of the rope and the rope in making the .second pass over the cutter will produce some fibers twice as long as the desired staple length. 40 It is apparent, therefore, that in the production of the desired length of staple, say 2 inches in length, and where the limits of variation in length are set at i inch, the contamination of this product with lengths ranging from 2, 3, 4 or even 10 or times this length, even though these cuts occur very infrequently and constitute, for instance, no more than 1 or 2 per cent of the total product, is sufiicient to render the product of little value for making spunyarn, or if it can be used .30 at all, it can be sold onlyasa decidedly inferior product.

It is, therefore,'an object of the presentinven- 7 tion to provide means forcollecting and removing excessively'long lengths of fibers during the cut 55 ting of staple from a rope of continuous filaments.

It is a specific object of this invention to provide such means in combination with staple cutlecting apparatus constructed in accordance with 1 the present invention.

Figure 2 is a front elevational view of the cardwheel and motor unit shown in Figure 1.

Figure 3 is a diagrammatic top plan view of a modified form of fiber collecting apparatus. 20

Figure 4 is a top plan view of Figure 1.

Figure 5 is a front elevational view, with parts shown in section, taken along the line 55 of I Figure 1.

Referring to thedrawings, reference numeral I I designates generally the base frame of a staple fiber. cutting apparatus of the type disclosed in the patent to Beria U. S. No. 1,723,998. A shaft I3 is journaled in the base frame and is provided with a filament rope advancing and tautening disc l5 at the upper end thereof. The shaft and. disc may be rotated by means of a belt (not shown) passing over pulley H. The disc I5 is provided ,with a funnel-like projection l9 anda conduit l8 passing radiallly from the funnel l9 to the periphery of the disc.

A staple cutting knife 2| is positioned closely adjacent the disc so that a filament bundle fed through the funnel l9 and conduit I8 is caused to be whipped into contact with the knife 2| thereby cutting short lengths of staple fibers from the filament rope.

A base member 23 is provided on the frame ll adjacent the knife 2|. The base member 23 is provided with grooves 29. A pair of clamping 45.

devices 21 which are adapted to fit within the grooves 29 are positioned within the grooves. The clamping devices may be fastened in the grooves at any desired point by means of bolts fastened to the motor 30. The motor can thus be fixed at the desired distance from knife 2|. A cardwheel 25 provided with card clothing 26 is positioned on a shaft 35 of motor 30. The cardwheel 25 is positioned adjacent the knife 2|, and is spaced such a distance from the knife that the card elements to the rapid rotation of the disc I5.

26 will be maintained a slightly greater distance from the knife than the length of the staple fibers being cut. This distance is illustrated by the letter X in Figure 1. r

In operation, the rope continuous filaments is passed downwardly into the funnel H3 at a predetermined rate of feed. The rope will be advanced through the funnel and the conduit l8 in the disc l9 by centrifugal force present due The rope will be passed, with considerable velocity, against the beveled edge of knife 2| thereby severing the rope into staple fibers. As indicated above, the knife will sometimes sever only a portion of the filaments of the rope. In this case the unsevered filaments will rotate in the disc [5 until the conduit I8 will again move the rope into contact with the knife 2|. As shown in Figure 4, the excessively long filaments 22 of the filament bundle 20 will project from the disc to such an extent that they will be caused to contact the card elements 26 and will thereby be caught on the cardwheel 25. The remainder of the fibers of the severed bundle will pass by the cardwheel 25 and may be caught in a container of any desired type. The excessively long fibers caught on the cardwheel 25 may be removed by hand or in any other desired manner.

Referring to Figure 3 of the drawings, the card clothing 26 may be mounted on an endless belt ll, and will function in substantially the same manner outlined above with reference to cardwheel 25. The use of the endless belt will, however, have the advantage that it may be passed over a small pulley 40 for cleaning of the card clothing. The card clothing which comprises a plurality of fine steel card elements or bristles 26 will be caused to open fan-like when passed over a pulley of small diameter. This is shown in Figure 3 where the card bristles 26 are passing around the pulley 40. At the point where the card bristles are caused to open, suction applied by means of nozzle 43, which is close to the ends of the card elements, will remove the fibers entangled thereon.

The cardwheel 25', or the endless belt lfl, may be maintained stationary during the operation of the staple cutting apparatus and only moved by hand to present a new surface and to clean the long fibers caught thereon. On the other hand, the cardwheel or the belt may be continuously moved in any desired manner such as by means of a motor as illustrated. The cardwheel may be positioned adjacent the knife 2| in a freely rotatable manner. 'The impact of the rope filaments with cardwheel will be suificient to gradually rotate the latter.

The card elements 26 should, at all times, be maintained at such a distance from the knife that the cut staple fibers which are of the desired length will not be caught thereon. If, for ex-- ample, the staple fiber being cut is 2- inches in length, the cardwheel will preferably be adjusted so that the projecting elements will not be closer than2 A to 2% inches from the cutting knife depending on the tolerance of the staple length 3 permitted in the product. Since the primary purpose of this collecting cardwheel is to remove exceedingly long lengths of cut filaments, and if mounted too close to the cutting knife it will pick up oil-length staple which 'can, however, be tolerated, in some cases it may be desirable to mount the wheel at a greaterfdistance from the cutting knife than 2% or 2 inches when producing an average staple length of 2 inches,

It is, of course, understood that numerous modifications may be made in this device. For' instance, instead of using card clothing, any other surface having fiber entangling elements such as brushes, bristles, fine teeth or the like may be used. The speed of movement of the wheel may in some cases be greatly increased over the speed indicated above, depending on the character of the wheel surface.

The cardwheel, or other equivalent device, hereinbefore described may collect single long length filaments, or full bundles, or ropes of filaments, or any portion of long length cuts of cut rope. By this device a relatively uniform staple product has been produced which can be formed into spun yarn without difliculty. Because it is now possible to eliminate these long cuts from the product, the usefulness of staple cutting apparatus of the type described in the Beria patent is more definitely established. It has been shown that even a commercially acceptable product can be produced by continuously crinkling ropes of continuous filaments of cellulosic material, such as cullulose acetate filaments, regenerated cellulose filaments, and the like, which crinkled filaments are out while tautened by means of centrifugal force. while the invention is especially useful in connection with a cutter of the type disclosed in the Beria patent, it can, of course, be used and to good advantage with any type cutter wherein the discharge from the cutting knife is made directly to an open bin and which is'subject to the occasional product of exceptionally long lengths of cut filaments.

Since it is obvious that many changes and modifications can be made in the above-described details without departing from the nature and spirit of the invention, it is to be understood that the invention is not to be limited to these details except as set forth in the appended claims.

Iclaim: I 1

1. In combination with a staple cutting apparatus of the type in which a rope of continuous filaments is advanced and held taut during the cutting thereof, by means of centrifugal force, a device for collecting and removing excessively long fibers which comprises a member containing a plurality of fiber entangling elements, said member positioned adjacent thecutting knife of said apparatus with the fiber entangling elements spaced from the knife a distance slightly exceeding the length of the staple fibers being cut.-

2. In combination with a staple cutting apparatus of the type in which a rope of continuous filaments is advanced and held taut during the cutting thereof, by means of centrifugal force, a device for collecting and removing excessively long fibers which comprises a member containing card elements; said member positioned adjacent the cutting knife of said apparatus with the card elements spaced from the knife 9. distance slightly exceeding the length of the staple fibers being cut. a

3. In combination with a staple cutting apparatus of the type in which a rope of continuous filaments is advanced and held taut during the cutting thereof, by means of centrifugal force, a device for collecting and removing excessively long fibers which comprises a rotatable member containing a. .plurality. of. fiber entangling elements spaced from the fibers being cut and means for rotating said member. I

4. In combination with a staple cutting apparatus of the type in which a rope of continuous filaments is advanced and held taut during the cutting thereof, by means of centrifugal force, a device for collecting and removing excessively long fibers which comprises a rotatable cardwheel, said cardwheel positioned adjacent the cutting knife of said apparatus with the card elements spaced from the knife a distance slightly exceeding the length of the staple fibers being cut.

5. In combination with a staple cutting apparatus of the type in which a rope of continuous filaments is advanced and held taut during the cutting thereof, by means of centrifugal force, a device for collecting and removing excessively long fibers which comprises a rotatable cardwheel, said cardwheel positionedadjacent the cutting knife of said apparatus with the card eleknife 'a distance slightly exceeding the length of the staple fibers being cut, and means for removing fibers from said cardwheel.

6. In combination with a staple cutting apparatus of the type in which a rope of continuous filaments is advanced and held taut during the cutting thereof, by means of centrifugal force, a device for collecting and removing excessively long fibers which comprises a rotatable cardwheel, said cardwheel positioned adjacent the cutting knife of said apparatus with the card elements spaced from the knife a distance slightly exceeding the length of the staple fibers being cut, and air suction means for removing the fibers from said cardwheel.

'7. In combination with a staple cutting apparatus of the type in which a rope of continuous filaments is advanced and held taut during the cutting thereof, by means of centrifugal force, a device for collecting and removing excessively long fibers which comprises a belt, card clothing on said belt, said belt positioned adjacent the cutting knife of said apparatus with fiber entangling card elements spaced from the knife a distance slightly exceeding the length of the staple fibers being cut, and means for removing fibers from said card clothing.

WILLARD PRESTON THOMPSON. 

